Lightweight helmets for head protection during bicycle riding falls and accidents have continuously evolved and undergone numerous improvements in recent years. One particular area of refinement has been in the removable attachment of accessories (such as visors, chin guards and ear flaps) to helmets.
U.S. Pat. No. 5,621,923 discloses an interface apparatus that uses screws to attach the visor and chin guard to the helmet. However, modern lightweight bicycle helmets are formed with a thin hard plastic shell surrounding a lightweight foam liner. The foam provides very minimal support for the screws, thus making the screw/shell contacts the primary support for the helmet accessory. The minimal contact between the thin plastic shell and the screw does not provide sufficient support to keep many helmet accessories securely attached to the helmet. For example, a chin guard must attach to the helmet in a manner to withstand a large impact force without becoming detached from the helmet. The screw contact with the thin shell layer of a modern lightweight helmet is simply not strong enough to withstand such impact forces. Further, repeatedly removing and reattaching the accessories with screws can wear out the hole in the thin shell further undermining the ability of the shell to securely engage with the screw.
U.S. Pat. No. 5,675,843 discloses a visor attachment apparatus using a semi-ball protrusion that engages an opening in a mounting plate. U.S. Pat. No. 5,333,328 discloses using hook and loop fastening patches to removably attach a visor to a helmet. While such attachment techniques provide a repeatably removable attachment between helmet and accessory, these type of attachments simply do not provide the requisite strength of attachment necessary for many types of helmet accessories. Chin guard impact forces, the weight of heavy helmet accessories, and/or visor wind resistance at high speeds can be too great for hook/loop or semi-ball/plate fasteners to keep the helmet accessories reliably secured to the helmet during use.
There is a need for a modern, lightweight helmet with an attachment apparatus that removably secures helmet accessories such as visors, chin guards and/or ear flaps to the helmet. Such an attachment apparatus needs to securely attach the helmet accessory to the helmet, yet be repeatable, reliable, inexpensive, and easy to manufacture.